They didn't make any 4 cylinders that would bolt in that I know of. I'm fairly certain that even if you could get one in there, the car is too heavy for it to make it worth it. The engine would probably be straining pretty hard to get all that heft up to speed.
As far as the gas smell in the oil, thats not rings, sounds like bad valve seals, or leaky injectors. Unless your car burns oil, your rings are still good. Gas is much thinner than oil and if it sits on top of the cylinders, it will find its way down into the crankcase.. leading me to believe that you have gas leaking down into your cylinders after the engine is off.
I'm not too familiar with the scangauge personally, so I'm probably not the best guy to ask.. I have one coming, so ask me again in a week
. Seriously, your best bet would be to ask in the instrumentation forum, someone there, who actually owns one, can probably answer those questions better, if you don't get an answer here from someone else.
You're very welcome for the reply and welcome to ecomodder
